Routine caregiving is stressful to the low birth weight (LBW) infant and has been associated with iatrogenic harm. Multiple caregiving activities performed in close time proximity (clustered) may overstress the LBW infants' limited energy supply and result in deteriorating or pathogenic physiological responses such as hypoxemia, acidosis, bradycardia, apnea, and intraventricular hemorrhage. This descriptive study will examine physiological and behavioral responses of LBW infants to clustered caregiving activities of more than and less than 15 minutes. Specific research questions for this study include: (1) Is there a difference in the ICP, HR, Sa02, and Activity level response patterns of LBW infants between caregiving cluster durations of less than 15 minutes and more than 15 minutes? (2) Is there a "critical" duration for continuous caregiving beyond which the majority of LBW infants respond with deteriorating physiological and behavioral parameters? (3) Is the duration of a cluster, the number of different caregiving procedures in a cluster, or the number of painful procedures in a cluster the most predictive of recovery time to baseline ICP, HR, and Sa02 changes? (4) Which combination of variables (demographic, historical, neonatal status score, caregiving activities, or duration) best predicts changes exceeding 1.5 standard deviations from baseline ICP, HR, and Sa02?